Hi guys,

I have a 2001 L with a whipple, full exhaust, twin 255s, accel super coils, denso plugs, accufab sbtb, sct2400.

I recently got the truck back from the dyno after the supercharger installation, soon after, the truck has started to idle high when I put it in park. The idle is at about 1100-1300 when in park, and about 750 in drive. I cleaned the IAC, I am about to try that again, the accufab throttle body is set up properly with the set screw stop and the tps voltage is at .98, it is not sticking open and there is no tension in the throttle cable. Can someone PLEASE help me with this, as it is very annoying, the dyno tuner is a big name tuner and he said that he did not put that into the tune. Thanks in advance for any help.

Sean

 

Check for an air leak. It should probably throw a code after awhile.........but that's just a guess.

 

I have checked every hose and double checked, when the whipple went on, I replaced every vac line and hose to do with the job, and every other one that was showing wear. The truck has had approx 150 miles with this problem and no codes.

 

I'm not a Turbo/Blown guy (see sig Haha!), but read this the other day. Maybe it will help.
https://www.f150online.com/forums/su...uum-leaks.html

 

I am convinced that this is not a vac/boost leak, everything else seems to be performing just as it is supposed to. I have triple checked everything this morning, the best way of describing what is going on, is it is like the throttle is getting stuck open a tiny bit. when driving, it also takes longer for the truck to get down to idle when coming to a stop.

Forgot to mention that I talked to accufab and they are confident that the throttle body is not the issue.

I also unplugged the IAC, then started the truck...it ran the exact same, maybe the idle went a bit higher (around 1400).

Wondering if I should put the tune back to stock with the sct tuner and see how the idle is, then putting my custom dyno tune back on, just to see if it is in the tune. I am scared to do this though because I'm not sure how, and am afraid I will lose the custom tune.

 

Well I'm already deeper in the woods on this one than I should be, so I better stop before I have to put myself on my own ignore list!

I'm sure someone with the proper knowledge will chime in shortly. Good luck with it.

 

Try unplugging the connector to the IAC. If it changes or almost dies, the then IAC is bad. Cleaning IAC has very minimal effect in most cases. If you replace the IAC be sure to get a Ford/Motorcraft part, others have reported rapid failures with aftermarket controllers.

 

I tried unplugging the IAC connector when the truck was off, and then started it and it ran the same, tomorrow morning I will try it with it running. Thanks

 

Ok, pulled the connector from the IAC with the truck , and it did not change a thing, so I guess the IAC is ok.

 

No change in IAC when unplugging it may mean that it is stuck open and not operating at all. Buy a cheap one and try it. Return it if it makes no difference.

 

Good call FireGuy, I will grab one when I get off of work tomorrow, and give it a shot. Looks like it will be a real pain in the *** because of the whipple air intake and the coil...hope I have patience tomorrow!

 

Thanks for the help.

 

I had the same exact problem a few years back. I don't have a Whipple. Turned out to be the Accufab TB. I actually took my almost new Accufab to them in person. He had the audacity to tell me the reason it idles higher was that the TB made more horsepower at idle, I aid WTF, bit my tongue and walked away. I will never go back to their products again.The also reassured me it could not be their product. If you have the stock TB, after trying the IAC and still have the problem, put it on as a test of air flow.

I put my Accufab on a light box and it was like daylight coming through the blade when it was closed. I ended up getting a LFP throttle body, higher quality and spot on perfect.

A lot of folks have a higher than normal idle with the Accufab and just put up with it, my theory is why waste gas at idle I would rather stuff it with my right foot.

I know I will catch hell from all the Accufab lovers out there, truth is they are all slightly different, some work great some don't. A quality control issue in my opinion.

 

I talked to a really helpful tech from accufab, and I was told that you are supposed to see light coming through all the way around the blade. I had to remove mine and check to make sure it had the light coming through evenly all around the blade...he said that is how you set it up properly. I didn't have a chance to pick up the iac today, I will grab one tomorrow and see what happens, if nothing, I will try the stock tb.

 

Well, this is the internet and you don't have to believe what I tell you. Accufab is "never" going to admit to any customer that their product is faulty, come on, really?

Check it against any other brand TB and you will see what I mean.

On another thought, if you try a new IAC and another TB and it still idles too high, the problem is narrowed down to either an air leak, or the tune.